Trap modulation spectroscopy of the Mott-insulator transition in optical lattices

TL;DR

This paper introduces trap modulation spectroscopy as a novel method to study the superfluid to Mott insulator transition in cold atomic gases within optical lattices, providing a new way to measure dynamical properties.

Contribution

The paper presents a new technique for probing quantum phase transitions in cold atomic gases, specifically applying trap modulation spectroscopy to detect excitations during the Mott transition.

Findings

Good agreement between experimental data and DMRG calculations in 1D.

Demonstration of the technique's effectiveness in measuring dynamical compressibility.

Application to both 1D and 3D systems shows broad applicability.

Abstract

We introduce a new technique to probe the properties of an interacting cold atomic gas that can be viewed as a dynamical compressibility measurement. We apply this technique to the study of the superfluid to Mott insulator quantum phase transition in one and three dimensions for a bosonic gas trapped in an optical lattice. Excitations of the system are detected by time-of-flight measurements. The experimental data for the one-dimensional case are in good agreement with the results of a time-dependent density matrix renormalization group calculation.